File CVE-2013-4537-qemut-ssi-sd-fix-buffer-overrun-on-invalid-state-load.patch of Package xen

References: bsc#962642 CVE-2013-4537

Subject: ssi-sd: fix buffer overrun on invalid state load
From: Michael S. Tsirkin mst@redhat.com Mon Apr 28 16:08:14 2014 +0300
Date: Mon May 5 22:15:03 2014 +0200:
Git: a9c380db3b8c6af19546a68145c8d1438a09c92b

CVE-2013-4537

s->arglen is taken from wire and used as idx
in ssi_sd_transfer().

Validate it before access.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

Index: xen-4.6.0-testing/tools/qemu-xen-traditional-dir-remote/hw/ssi-sd.c
===================================================================
--- xen-4.6.0-testing.orig/tools/qemu-xen-traditional-dir-remote/hw/ssi-sd.c
+++ xen-4.6.0-testing/tools/qemu-xen-traditional-dir-remote/hw/ssi-sd.c
@@ -221,8 +221,17 @@ static int ssi_sd_load(QEMUFile *f, void
     for (i = 0; i < 5; i++)
         s->response[i] = qemu_get_be32(f);
     s->arglen = qemu_get_be32(f);
+    if (s->mode == SSI_SD_CMDARG &&
+        (s->arglen < 0 || s->arglen >= ARRAY_SIZE(s->cmdarg))) {
+        return -EINVAL;
+    }
     s->response_pos = qemu_get_be32(f);
     s->stopping = qemu_get_be32(f);
+    if (s->mode == SSI_SD_RESPONSE &&
+        (s->response_pos < 0 || s->response_pos >= ARRAY_SIZE(s->response) ||
+        (!s->stopping && s->arglen > ARRAY_SIZE(s->response)))) {
+        return -EINVAL;
+    }
 
     return 0;
 }